Australia in April 2010

In Brief

April was significantly warmer than normal over most of Australia, especially at night. Overnight minimum temperatures for
Australia were the second-highest on record for April, and ranked in the top three in four states. Maximum temperatures were
less extreme but were still well above normal. Rainfall was also above normal over much of the country, particularly in the
interior, although it was near or below normal in many southern areas.

Temperatures

Maximum temperatures were 0.93°C above normal (10th highest on record). The most significant warmth was in Western Australia,
which was fifth-warmest on record. Daytime temperatures were at least 1°C above normal over most of the state except the north
Kimberley and the western coastal strip, and were 2°C or more above normal over most inland, with anomalies reaching +4°C
around Warburton. Records were set locally in the inland Pilbara. Anomalies exceeding 1°C extended into the southwestern
Northern Territory and northwestern South Australia. Another area which was at least 1°C above normal was in the coastal
southwest, encompassing all of Tasmania, and the eastern coastal strip between Geelong and the NSW-Queensland border.

The most significant area with below-normal maximum temperatures was a region centred on the Gulf region of northwestern
Queensland and the eastern Northern Territory, with temperatures more than 1°C below normal along the Gulf of Carpentaria
coast in both the NT and Queensland. Elsewhere, only a few patches had daytime temperatures slightly below normal, including
areas around Mount Gambier, exposed WA coastal areas around Carnarvon and Geraldton, and some areas along the inland NSW/Queensland
border.

Overnight minimum temperatures were 1.68°C above normal, the second-highest on record (ranking only behind 2005). Western
Australia ranked second, and South Australia, Tasmania and Victoria all third. They were above normal almost throughout the
country, the only exceptions being the far southwest of Western Australia and coastal parts of that state’s Gascoyne region.
Most areas were at least 1°C above normal, except for western WA (west of a Port Hedland-Kalgoorlie-Esperance line) and the
eastern half of NSW.

The strongest anomalies, more than 2°C above normal, occurred in the eastern half of Western Australia, most of the Northern
Territory outside the Top End, northern South Australia, northwestern Victoria, and central and western Victoria. Anomalies
exceeded +4°C around Warburton (WA), and east of Alice Springs and in the Victoria River district of the Northern Territory.
Records were set in a number of regions, including much of the WA interior, the western Top End (NT), the central third of
Victoria, northwestern Tasmania, parts of Cape York Peninsula, and around Ceduna (SA).

Rainfall

National rainfall was 34% above normal (17th highest on record). Totals were above normal across much of northern and central
Australia, including almost all of the Northern Territory, Queensland west of a Townsville-Charleville line (extending into
northwestern NSW west of Walgett), most of South Australia (except the Eyre Peninsula and some areas east of the Flinders
Ranges), and the eastern half of Western Australia. It was also wetter than normal in April in the western half of Victoria,
as well as in the northeast ranges and south Gippsland, and in northwestern Tasmania.

The two most significant areas of above-normal rainfall were in much of northeastern South Australia, and the Gulf region
extending from the eastern Northern Territory as far east as southern Cape York Peninsula. April records were set in both
regions, around the Queensland/NT border on the Gulf coast, further east around Croydon, and in the Woomera-Leigh Creek area
in South Australia. Other areas with totals in the highest decile included the southern NT around and east of Alice Springs,
and localised areas in the WA Goldfields, the NT Top End, and west of Bourke in New South Wales.

While rainfall was below normal in many southern areas, few areas were especially dry and only small areas were in the lowest
decile. The greatest concentration of such areas was on the NSW coast south of Sydney; there were also patches of such low
falls scattered through the inland west of Western Australia.

Notes

The Monthly Climate Summary is prepared to list the main features of the weather in Australia
using the most timely and accurate information available on the date of publication; it will generally not be updated.

This statement has been prepared based on information available at
10 am on Monday 3 May 2010.
Some checks have been made on the data, but it is possible that results will change as new information becomes available,
especially for rainfall where much more data becomes available as returns are received from volunteers.

Long-term averages in this statement and associated tables are for the period 1961 to 1990 unless otherwise specified.

In the tables, fractional ranks denote tied values.

A new area-averaging method was adopted for rainfall in May 2009. Current and historical totals for Tasmania are substantially higher than under the old scheme, but differences for other states, and nationally, are negligible.
The rankings and departures from mean shown here use the new method.